


Into the woods

by Nippykat10



Category: Dr. STONE (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime)
Genre: Abandonment Issues, Aftermath of Torture, Attempt at Humor, Canon-Typical Violence, Demon slayer but in a modern universe, Demons Are Assholes, Family of Choice, Found Family, Government Conspiracy, I'm Bad At Tagging, Multi, Not all demons are assholes, Relationship Discussions, Religious Discussion, Slight slice of life, asexual Tanjiro, comedy is good, discussion of philosophy, discussion of sexuality, discussion of the atomic bomb and the aftermath, discussion of world war 2, some sex stuff
Language: English
Status: In-Progress
Published: 2019-12-07
Updated: 2020-01-31
Packaged: 2021-02-26 00:27:35
Rating: Mature
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 3
Words: 3,307
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21714541
Author URL: https://archiveofourown.org/users/Nippykat10/pseuds/Nippykat10
Summary: Senku was never one to believe in demons, after all it wasn’t logical in anyway. All the blood and flesh eating, they were just myths to keep curious people from going out into the dark. That is until 3700 years later when he was unpetrified and was attacked by one. Now along with a girl named Yae and a demon slayer named Tanjiro he must unravel the secret and the science behind demons and demon slayers. All in the name of science and the safety of humanity.
Relationships: Agatsuma Zenitsu/Kamado Nezuko, Hashibira Inosuke/Kamado Tanjirou, Ishigami Senkuu/Original Female Character(s), Senku/oc
Comments: 2
Kudos: 20





	1. What’s in the woods?

**Author's Note:**

> I have to thank Bridgy_Kathleen for letting me borrow her original character

**Summary for the Chapter:**

> In which tanjiro awakens to a new crazy world

_How long? How long has it been? Since that green light? Since …where was his little sister? Was she even still alive? Was she dead?_ He was vaguely aware of the world around him. It got harder and harder to stay conscious with every passing day. He didn’t know how long he stood still in this petrified form. Weeks, months, years, decades, centuries? How long has it been? Since he saw the sun? 

Then, a bright light. It followed by cracking and air finally filling into his lungs. He gasped for air followed by more cracking and breaking of stone. He looked down and saw that the stone that had held him prisoner was now gone. It was broken and shards of stone covered his naked body. 

Oh yeah,he was naked. Where did his clothes go? He looked at his right hand and saw that his sword was still in his hand. It was all rusted and was broken. Didn’t he just get it? It was brand new since his previous sword broke from when he fought that albino spider demon Rui. He knew that Mr.Haganezuka will kill him for being so negligent.

  
Tanjiro heard gasping and gurgling and saw a person he looked at the person. He was on the ground struggling with a demon on top of him.   
  


He looked very strange, for starters his hair stuck out like he had put his finger in an electric socket and it was white with green tips. He had two strands that hung in his face and had red eyes. He wore some sort of animal skin wrapped around his body like a bath robe.

He stopped gawking at the person, took a breath, and then ran at the demon. _Water breathing first form! Water surface slash!_ He thought when his rusted beyond blade went through the demon’s neck. The demon’s head spun and went one direction while his body went in the other direction, Spraying the poor guy who was attacked with blood.

The person with the wild hair gasped and started to cough grasping his neck. He then sputtered to try to get the blood out of his mouth and crawled away from him and the demon’s body that began to disintegrate. He looked at him, sharp and smart red eyes were analyzing him and his attack.

“You just killed him,” he said bluntly. 

“Yeah, but he wasn’t human. He was a demon.”

“Yeah right, demons don’t exist.” He replied. “That was just a cannibal, although I wonder how he got out of petrification.” He said 

The wild haired person proceeded to get up, only to stumble a bit when he noticed that the person ankle had a bite mark that was bleeding. 

“Don’t just stand there, can you hand me my bag?” Wild hair said.

“Oh uhh, sorry.” He said sheepishly as he handed him the bag. “Although now that I think of it, that person you just killed did have really sharp teeth. What’s with that?” Wild hair question out loud. 

“That was a demon. I should know I’m a demon slayer.” He replied.

“I thought demon slayers were just a government conspiracy,” Wild hair mused while he tied a piece of cloth around his wounded ankle.

“The body gone though, it disintegrated after you cut his head off, by the way thanks for getting blood all over me.”   
  


“Sorry about that,” he replied. “Uhh my name is Tanjirou Kamado, what’s yours?” “It’s Senku” Senku replied then smirked.


	2. Why the hell did I go into the woods?

**Summary for the Chapter:**

> Senku’s first interaction with the world of demons and he meets a demon slayer

Senku did not trust Tanjiro, not one bit. Truth be told he never even wanted to revive him, he just wanted the broken sword since it seemed that the crossbow he used on that cannibal or rabid person didn’t affect it. There is no way that demons exist. It’s not logical for a biped to go up in flames at the mere touch of sunlight or ultraviolet rays. Nope, no way. Although if it was rabies that what that person had… well he’d be doomed in this Stone Age world. Since he got bit by that person.

“Um excuse me, do you have any clothes I could borrow please?” 

Senku blinked and looked at Tanjiro who was trying to cover himself with his hands. His reddish black hair had a few clumps of stone in it, along with a piece of stone hanging on the left side of his forehead. The new crack scar went down from his right temple to his left cheek and sort of split under his red eyes. Huh he wasn’t acting robotically anymore, maybe if someone wasn’t fully conscious all the time in the petrified state they’d be a little disoriented for a while. Put a pin in that thought he thought to himself. Actually put ten billion pins in that thought. Almost forgot his catchphrase.

“We can get you some clothes back at camp, no one’s going to care if your butt showing or your dick’s hanging out.”

Senku replied. That caused Tanjiro to really blush. “Uhh sure,” Tanjiro said following him.

* * *

_He knew better than to just go and investigate a scream in the middle of the woods at night. Come on! He’s a man of logic and reasoning, not impulse and emotional actions! But still Taiju and Tsukasa had worked really hard today, and even if he didn’t trust Tsukasa, no one deserved to be overworked and exhausted all the time. Senku knew the feeling of overworking and exhaustion, it could potentially kill them in this world._

_So here he was with his crossbow, in the middle of the night, in creepy woods with just the moon as lighting, running to investigate a potential human being reawakened from the petrify. Senku was getting closer, but the area that the scream came from was not near any cave or near any other source of nitric acid. Instead it was in the middle of a deep dark forest. Mist hung in the air for some reason, there was barely any light from the moon._

_Senku accidentally stepped on a twig which made him jump a little._ Goddammit! _He thought._ I’m not cut out for this _!  
As he finally approached the place where he heard the scream he paused and then hid behind a tree._

_It was a person wearing old robe that looked like they were from the taisho period. Long nimble fingers dug into some sort of carcass as he pulled out one after the other of pieces of flesh and meat. The man chomped and sucked at the carcass, seemingly finding the utmost pleasure in devouring the creature. Senku noticed pearly white fangs poking out of the man maw as they gleamed in the remaining moonlight. Horns as thick as clubs and sharp as needles stuck out of the man’s head and we’re covered in blood._

_Senku squinted his eyes a bit at the carcass, only to realize in horror that the so called animal carcass was in fact a human corpse. The body was covered in its own blood and the neck was at an odd angle. Most likely cause of death was strangulation. Senku could actually see the cannibalistic person ripe out the stomach of the poor unfortunate soul, and began to devour it like someone would devour a piece of cake._

_Senku actually gagged at the sight and proceeded to throw up all over himself, covering his tunic in vomit. I have to get out of here! He thought. this was so wrong! Even in the stone world no one should ever resort to cannibalism! The mere thought of the idea to eat someone else in order to survive was just so wrong!_

_As Senku very slowly started to back away from this horrible scene, he once again stepped on a stupid stick and it cracked with a loud snap! Oh shit. Senku thought._

_“ **Huh? What? Who is there?”** _

_The cannibal called out. “ **Hey you human, get out of my turf dammit! This isn’t some show!”**_

_Senku froze as the cannibal stood up and growled at him. Senku whole body was starting to shake. The cannibal sniffed at the air, then laid his eyes on Senku’s tunic where he had drawn the e=mc2 equation in his own blood._

_“ **A rare blood type huh? I having eaten one of you in over four thousand years.”** He grinned. He knew that it was time to get out of here._

_Senku began to run as fast as he could. Through his labored breaths he could hear the cannibal laughing in maniac glee as he chased after him shouting_

_“ **I’m gonna get ya! I’m gonna get ya!”** He tried to shoot at the person with his crossbow, but even though it went through his neck all it did was stun the cannibal a little. Senku ran and ran as fast as he could until he ended up tripping and scraping his hand on some dull yet sharp._

_When he fell on the ground he noticed that what he had tripped over was a statue of a boy that was a little younger than he was carrying a real sword in his hand. The boy had a determined look on his face as if he was going to cut the very green light that petrified him. Senku tried to get the rusted sword out of the boy’s hand without breaking the statue since even in the stone world he didn’t want to be a murderer, but the blade would not budge._ Come _on! He thought to himself._ I don’t want to waste more of the revival fluid on some complete stranger. Not just yet anyway.

_**“Found you!”** _

_The cannibal screamed as he caught up to Senku. Looks like I’ve got no choice. He thought and proceeded to dump the rest of the fluid onto the statue before a sharp pain in his right ankle came._

_“_ _**Got yo** **u! Now I’m going to enjoy some marechi blood finally!”**_

_The cannibal gleefully exclaimed as he grabbed Senku’s neck and began to squeeze. Senku tried to push the cannibal off of him only for the cannibal to grow bigger and more stronger and black dots began to float in his vision. No! I can’t die! I have to bring back civilization! I can’t die like this! Senku thought as vision of his past life sprung in his head. Of his adopted father, his friends, his schoolmates, and that one girl who almost was as smart as he was in school. Yae Sawa, that was her name. She always did give a run for his money._

_“Water surface slash!” Someone cried out as the cannibal head was sliced right off his body. Spraying blood all over Senku’s face as the body collapsed on top of him and at the same time let go of his neck. Senku gasped and drank in the much needed air for his brain. After he coughed a few times he then pushed the body off of him before noticing that the body was starting to disintegrate. Senku scooted away from the body and then finally looked at the boy to killed him._

_He was probably of average height with a little bit of muscle mast and deep throbbing veins in his arms. His red eyes showed both tiredness and pity at the same time. His skin was tanned most likely from working out in the outdoors a lot, and he had a deep burgundy red hair as well. Who on earth was this kid? Senku thought._

_“You just killed him! What the hell!” Senku yelled. The boy looked at him with dull eyes only to then blink and rub them. After doing that the boy yawned and then sighed._

_“He was a demon, and he was attacking you.”  
_

_senku scoffed_

_“yeah right, demons don’t exist, he probably was just a cannibal rabid person.”_

_The boy frowned at that statement then looked at Senku’s clothes with a gross expression. Senku looked done and realized that his tunic was covered in both blood and vomit. Though for some reason the blood was starting to disappear._

  
  
_senku looked back behind him and noticed that the body was gone.  
_

_“I’m a demon slayer. I uhh work with the demon slayer Corp.” the boy explained._

_Senku scoffed at that comment “isn’t the whole demon slayer Corp a government conspiracy? Like Area 51 in America holding aliens?” Senku questioned._

_Did he really revive a crazy conspiracy theorist? If he has to deal with one more picture of a supposed Bigfoot sighting so help him god. He had dealt enough with that in the science club._

_”I’m Tanjiro Kamado by the way, thank you for getting me out of the stone.”_

_Tanjiro then bowed politely at Senku. “Ehh?” Senku picked at his ear with his pinky. So there going with names now huh? Alright then._

_“My name is Senku, I don’t think family names are going to work any more in the stone world,” Senku said then sighed._

_“Alright, cmon I’ll take you back to my camp and get you some clothes.”_

**Notes for the Chapter:**

> Once again I thank the person who let me borrow Yae Sawa Brigid Kathleen you’re awesome!


	3. The demons

**Summary for the Chapter:**

> “The way is clear, the light is good, I have no fear nor no one should, the woods are just trees, the trees are just wood”- into the woods prologue

* * *

Yae knew it was forbidden to go out of the village at night, or else the demons will come. But something really just compiled her. A name that was not her own was the one thing she could remember, besides her own name. Senku.

Who is Senku? Why was that name the only thing she could remember? 

Yae pondered this to herself as she watched Chrome packing up the materials he had collected through the day. He was an interesting boy to say the least. With his brown hair that was tied up with rope. And his brown eyes that showed much more intelligence in them than the other people in the village, yet showed kindness in them when he would look at her. Or maybe it was pity.

“That’s about everything Yae, you better get back to the village before the demons come,” Chrome spoke as he lifted a heavy rock and placed it to the side of his hut.

“I know that, but I still don’t understand why you want to be out near the edge of the village.” Yae protested. 

Chrome blew air out of his mouth in a huff. “Someone got to be out to mark where the barrier ends, otherwise we won’t know where the goddess sorcery ends. She sometimes shortens the barrier.” Chrome replied.

Yae knew why Chrome was so determined to keep knowing where the barrier begins and ends, his parents were killed by demons while on a hunting trip way before she arrived. They had thought that they were in the barrier while they were being chased but they didn’t make it and died right in front of Chrome. What's worse is that he saw his parents being eaten in front of him. After that the entire village would pity Chrome which led to him leaving and living on the edge of the barrier.

“So has it be shortened or what?”Yae asked looking down.

“Not sure yet best get behind me.” Chrome then took out a sharp rock knife and proceeded to cut his left palm.

  
  
Yae knew what was going to happen, because I Chrome and most of the villagers had a special blood type that would cause demons to go into a frenzy. Just one drop of blood was like triggering a shark with blood, they could smell it a mile away.

Yae was honestly extremely afraid of demons. When she awoke about a couple of months ago with no memory and completely naked, she was lucky that she was found by Kohaku during the day. Yae didn’t want to think what would’ve happened if she had out at night. Honestly she and Kohaku barley made it to the village by nightfall, and if it wasn’t for Kohaku’s speed, most likely they would’ve been eaten. 

Yae shuddered at the thought, that demon still haunted her dreams. The crazed look in its eyes, like a rabid dog out for blood. The way it chased both of them on all fours while Kohaku carried Yae on her back. Its horrible long tongue. Although it was kind of funny when it ran right into the barrier and looked like someone who had run into a glass door…

Why was it that she could remember glass doors and other things like her period, but not major things like where she came from and her parents? Meh psychology and brains are weird. 

Yae watched the sun set as chrome took a step outside where he had placed the stone. He cupped his hand that he had cut as the blood pooled in his palm, then at the final dusk mark let the red liquid fall onto the ground.

“Now we wait,” Chrome muttered.

Yae squinted at the ground where the puddle of blood lay on the ground. Soon enough, just as the sun set a demon charged right at them.

**“Marechi! I want that rare blood!”** It roared.

“Run!” Chrome yelled as the demon charged at him. Yae followed with a scream as they ran back to Chrome’s hut. Yae stumbled a bit almost giving the demon a chance to get her, but just as it tried to pounce, it’s face got smashed like it had ran into a door.

Yae gasped for air as she was bending over trying to catch her breath. Chrome was bent over too.

“Damn, these things are getting faster,” he said out of breath. Yae nodded her head in agreement, the demon still growled and clawed at the barrier. Chrome very gently pushed the rock to the demon as a way to measure. The demon roared and slashed at his calf, Chrome yelped in pain and pulled back. 

“Yeah it’s getting smaller, just as I thought.” Chrome motioned for Yae to follow him back to the village.

“let’s go, Kohaku and the others are probably worried that your spending too much time with me. Yae winced at that, it was no secret that many in the village thought that Chrome was weird one. Mostly because his body was weak and he preferred to collect plants and minerals than to fighting and weapons. Besides Kohaku and Ruri and herself, Chrome didn’t have any other friends. 

* * *

Yae nodded to Kinro and Ginro as she and Chrome passed them on the bridge. The former still looked at her with distrust, while the latter looked bored and distant, probably daydreaming about cute girls. Yae then turned to Chrome and waved goodnight to him passing Suika and the other children along the way to her hut. Yae waved at Kohaku who was skinning a deer, Kohaku nodded at Yae as she flipped open the hut flap door. 

Humming to herself, Yae began to unravel her braid and change her blue dress and black leggings off in exchange for her simple night dress. Yae looked at her reflection in the bowl of water on the chair that was used for self grooming. Her black hair was all clunky and had a few knots in it from the braid. Brown eyes stared back at Yae even though she couldn’t see them very well. 

How strange it was that her appearance looked way different than the rest of the villagers. Unlike the other girls in the village, she did not have the plump lips, instead having thin lips, and her eyes were shaped different too. Yae shrugged to herself at the thought. It didn’t really matter on what you looked like, just as long as you helped out the village and survived is all that matters. Yae yawned to herself and covered her mouth as she pulled back the furs she used as covers to get into her bed. It was time to get some sleep and try to figure more out about demons tomorrow anyway.

  
  


**Notes for the Chapter:**

> Yae belongs to her respected owner bridgey Kathleen I love ya girl!


End file.
